Merits and Challenges of Ruddlesden–Popper Soft Halide Perovskites in Electro‐Optics and Optoelectronics

• Published in: Advanced materials (Weinheim) Vol. 31; no. 1; pp. e1803514 - n/a
• Main Authors: Chen, Zhizhong, Guo, Yuwei, Wertz, Esther, Shi, Jian
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-01-2019
• Subjects: challenges; Charge transfer; Design engineering; Emitters; Emitters (electron); Optoelectronic devices; Organic light emitting diodes; Perovskites; Photovoltaic cells; photovoltaics; properties; Properties (attributes); Ruddlesden–Popper halide perovskites; Solar cells; challenges; photovoltaics; properties; Ruddlesden-Popper halide perovskites
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201803514

Following the rejuvenation of 3D organic–inorganic hybrid perovskites, like CH3NH3PbI3, (quasi)‐2D Ruddlesden–Popper soft halide perovskites R2An−1PbnX3n+1 have recently become another focus in the optoelectronic and photovoltaic device community. Although quasi‐2D perovskites were first introduced to stabilize optoelectronic/photovoltaic devices against moisture, more interesting properties and device applications, such as solar cells, light‐emitting diodes, white‐light emitters, lasers, and polaritonic emission, have followed. While delicate engineering design has pushed the performance of various devices forward remarkably, understanding of the fundamental properties, especially the charge‐transfer process, electron–phonon interactions, and the growth mechanism in (quasi)‐2D halide perovskites, remains limited and even controversial. Here, after reviewing the current understanding and the nexus between optoelectronic/photovoltaic properties of 2D and 3D halide perovskites, the growth mechanisms, charge‐transfer processes, vibrational properties, and electron–phonon interactions of soft halide perovskites, mainly in quasi‐2D systems, are discussed. It is suggested that single‐crystal‐based studies are needed to deepen the understanding of the aforementioned fundamental properties, and will eventually contribute to device performance.
Recent advances in Ruddlesden–Popper quasi‐2D perovskites are reported. After detailed comparison of the crystal structure, growth mechanism, charge‐transport properties, and carrier dynamics in 2D and 3D perovskites, the advantages and challenges of quasi‐2D perovskites are discussed. Finally, electron–phonon interactions and polaritonic emissions in these materials are reviewed.